Segmentary sealing blades for rotary engines



L. PERAS March 30, 1965 SEGMENTARY SEALING BLADES FOR ROTARY ENGINES 5Sheets$heet 1 Filed March 15, 1962 FIG.2

/ izwm a r 3,175,503 SEGMENTARY SEALING BLADES FOR ROTARY ENGINES LucienPras, Billancourt, France, assignor to Regie Nationale des UsiuesRenault, Billancourt, France Filed Mar. 15, 1962, Ser. No. 179,931Claims priority, application France, Mar. 31,1961, 857,549, Patent1,293,169 10 Claims. (Cl. 103-130) This invention relates to bladesadapted to seal the joint between the component elements of rotaryengines which are subjected to the compression and expansion of thegases accomplishing their power stroke in working chambers.

3,175,503 PatentedMar. 30, 19,65

FIG. 4 illustrates in fragmentary section a rotary engine wherein thegeneratrices of rotor 1 are not deformed and wherein a single blade canprovide the fluid-tightness due to its eflicient engagement with therotor surface. In this figure 1 is the rotor, 2 the stator, 3 and 4 theend flanges, 5 the joint and 6 the blade spring.

It has already been proposed to use one-piece deformable sealing bladeshaving properties enabling them to accommodate the deformations of theaforesaid component elements.

The sealing blades according to the present invention are segmented inorder to accommodate as fully as possible the generatrices of the rotoror cases of rotary engines.

The blade may be segmented as simply as possible, that is, into twoelements for very narrow rotors, but the higher the number of segments,the better the result, and this number is unlimited except for thecomplication arising from an excessive number of elements.

The invention will be described hereinafter with reference to theattached drawing wherein:

FIGURE 1 is a section taken across a rotary engin equipped withsegmental blades;

FIGURE 2 is a fragmentary section taken upon the line IIII of FIG. 1;

FIGURE 3 is a fragmentary section showing on a larger scale a detail ofthe cross section of FIG. 1;

FIGURE 4 is a front view showing a unitary blade disposed between therotor and stator of the rotary engine, and

FIGURES 5 to 13 are similar views showing different forms of embodimentof segmental joints fitted in corresponding slots of rotary engines.

In the drawings, FIGS. 1, 2 and 3 areshown only to remind the structureof a rotary engine. In the example illustrated the four-lobed rotor 1revolves within a stator 2 formed with five chambers and provided withside flanges or plates. The stator 2 comprises in slots or grooves 7sealing blades 5 adapted to isolate the chambers from one another bybearing against the rotor 1. To this end, springs 6 fitted in the bottomof grooves 7 urge the blades against the rotor. As is quite obvious fromFIGURE 1, thestator has an inner wall which encloses a chamber Withinwhich the rotor can rotate. As is well known and as is also seen fromFIGURE 1, the rotor and stator have parallel longitudinal axes. Thestator inner wall specifically defines a plurality of concave recesses40 adjoining each other at apices 41. The rotor has a peripheral surfacewhich defines in radial cross-section a plurality of convex lobes 42whose convexity substantially corresponds to the concavity of therecesses 40. As is also seen in FIG- URE 1, the number of lobes 42 isone less than the number of recesses 40. Each apex 41 comprises a groove7 within which is located the sealing meanscomprising the aforementionedblades 5 and resilient biasing means 6.

It will be seen from FIGURE 1, that as the rotor rotates, its peripheralsurface will slide past and against each of the sealing blades orelements 5. This continual contact between the rotor periphery and theblades 5 permits effective separation and sealing of the adjacentcompartments formed between the rotor and stator wall.

FIG. 5 illustrates a rotor 1 of which the shape can be altered mainly byits expansion due to the gaseous combustion in the working chambers.

According to this invention, each sealing blade is divided into aplurality of blade segments resiliently urged by separate springs. Thesesegments position themselves automatically along tangents to the curvesof the rotor generatrices moving past the blade segments inserted in astator slot or groove. FIG. 5 shows clearly the improvement resultingfrom this arrangement if there is considered the chord a, the deformedgeneratrix b and the tangents 8, 9 and 10 to this generatrix.

FIG. 6 shows segments assumed to move parallel to their position in thecold state. In this case the advantage resulting from the segmentalblade disposal is moderate for it is clear that the blade should bedivided into a greater number of segments, as shown in FIG. 7. These:segrnental elements 11, in the example illustrated in FIG. 7, are tenin number, each element being provided with a separate spring 12engaging a recess formed in each segment 11 and bearing against thebottom 13 of the slot 14 formed in stator 2.

FIG. 8 shows an embodiment comprising a great number of segmentalelements 15, a single-coil spring 16 of generally flattenedcross-section ensuring the desired resilient engagement with the rotorgeneratrices. The reference numerals 17, 17' and 18 designate incross-sections typical examples of the coil-spring cross-sectionalshape, the first two examples showing flattened springs and the thirdexample a circular spring.

FIG. 9 is another illustration of a deformable seg mental blade whereinthe segments 19 are of inverted T configuration and the springs 20 reactagainst the side arms of each T and against the bottom of the statorgroove.

It may beadvantageous to provide a series of segments interconnectedthrough flexible, spring-like members to facilitate the mass-production,storing and checking operations. The length of the segmental blade caneasily be ascertained after assembly to check the axial plays betweenthe assembled blade segments and the side flanges or plates.

FIG. 10 is a view similar to FIG. 9 and shows a modified embodimentwherein adjacent springs are linked by a ring 21.

FIG. 11 shows another form of embodiment comprising a plurality ofsegments constituting a deformable sealing blade wherein each segment22, 22 is formed with a notch 23'on its upper face, each notch 23 beingengaged by a correspondingly shaped portion of a single spring 24consisting of a wire or a flat strip.

FIG. 12 illustrates another embodiment of a series of interconnectedsegments wherein each segment 25 is formed with two notches 26, 27, aspring 28 of adequate configuration engaging the adjacent notches of twosuccessive' segments. Y

FIG. 13 is another embodiment wherein the segments 29 also of inverted Tconfiguration are each urged against the rotor by two coil springs 30,31 disposed on either side of the central member of the T and adapted toengage a correspondingly notched counter-plate 32 acting on the one handas a spring-receiving member and on the other hand as a stop to limitthe radial movement of the segments by reserving a predeterminedclearance.

As will be seen in FIGURE 13, the counter-plate 32' and sealing elements29 have corresponding abutment portions 43 and 44 which serve to preventfurther outward radial movement of the blades 29 afterthe springs. 30have been compressed to a certain point. i

Moreover, this counter-plate 32fillsthe maximum volume of theblade-receiving groove, which maybe advanfageous for reducing; deadspace and thus prevent a non negligible fraction of gas' from'circulating along the groove. p 7 V The bearing of this invention is notlimited by the specific forms of embodiment described with reference-to,the attached figures but extends to any otherembodiment consistent withthe spirit and scope of the patent, which resides in dividing a sealingblade into segments either free or interconnected by spring links inorder to ensure a satisfactory and'reliab'le fluid-tightness alongv thedef formed generatrices of the rotor, or along the side flanges orplates of the stator in rotary engines.

I claim? 1". A rotary engine comprising a stator having an inner wallwhich defines a hollow compartment, said wall defining in radialcross-section a plurality of angularly adgroove, said spring comprisingstraight portions which abut said stator and curved portions betweensaid straight tudinal axis being substantially transverse to the radialline of travel of said sealing elements, said coil. spring being locatedbetween the bottom of said groove and the rear face of said sealingelements with its helical coils being transversely compre'ssedb'etweensaid sealing elements. and the bottom of said groove.

7.v The engine of' claim 4, wherein the rear face of each of saidsealing elements comprises two longitudinally spacedv recesses, saidbiasing. means in each of said grooves comprising a pl'uralitygofflat-type springs having an arch joining concave recesses and aninwardly protruding apex at each point of juncture between t-woadjoining recesses, a rotor mounted within said compartment along'alongitudinalaxis which is parallel to the longitudinal axis ofsaidstator, said rotor having a peripheral surface which defines inradial cross-section a plurality of convex lobes, each lobe being curvedsubstantially to the same curvature as eachof said recesses, said statorcomprising a longitudinal groove at each of said apexes, 'a sealingmeans in each of said grooves, each said sealing means comprising aplurality of separate sealing elements longitudi- 'nally aligned andabutting each other on adjacent radial faces, and biasing means in saidgrooves separately urging each of said element-s radially inwardly insealing contact against the peripheral su'rface'of-said rotor, saidrotor being rotatable about its longitudinal axis with'its periph eralsurface slidingpast each of said sealing elements, said peripheralsurface of said rotor defining with said stator inner walllongitudinally extending chambers which i are sealing ly'separated fromeach other by said sealing and said sealing elements, said plate membercomprising longitudinally aligned notches, saidspring members being coilsprings and each said coil spring fitting in one of said notches andbeing compressed between said plate member and'said sealing elements,said plate member and said sealing elements comprising respectiveabutment portions radially aligned with" each other and radially spaced"apart, said abutment portions serving to limit the outward radialmovementof said sealing elements by abutting: against each other. whenthe spring elements'are V compressed beyond" av certain degree. 7

.4. The engine of claim 1, wherein said: sealing elements each have fiatfront. faces which contact said rotor periphery, said sealing elementseaelr having a recess int-heir rear faces, saidl'biasing means beingreceived in each of saidrecesses. 5 p 1 5.. The engine of claim 4,wherein said biasing means in each of said grooves is a singleblade-type spring extending substantially the full length of itsassociated portion and opposite end portions, said arch portionabutting, the bottom of said groove and the opposite end portions of anyone spring, being received'in adjacent ones of said' recesses indilferent ones of said sealing, elements.

8. The engine of claim 2, wherein each of-said sealing elements has aninverted T-shape and each of said spring members are blade-type springs,each of'said bladetype springs abutting against opposite-sides of thehorizontal leg, of the T, with the vertical leg ofrthe T fittingbetween'opposite ends of saidspring.

9; A rotary engine comprisingv a stator and a rotor rotatable withinsaid stator, said stator comprising an inner wall and said rotorcomprising an outer peripheral surface, saidrotor and stator definingbetween said wall and said surface a plurality of'separatesealedchambers, each chamber extending. longitudinally along the full axiallength of said rotor surface, said chambers being disposedcircumferentially adjacent to each other, sealing means sealinglyseparating adjacent chambers from each other, said sealingv meanscomprising longitudinal grooves circumferentially spaced apart in saidstator, a plurality of separate sealing elements in each groove, saidelements being longitudinally aligned and abutting one another alongradial faces thereof, each of said elements being separately slidable ina radial direction in said groove, resilient biasing means separatelyurging each of said elements inwardly towards said rotor, said elementssealing.- ly contacting. said rotor peripheral surface.

10. The engine of claim 9, wherein said biasing means comprises ablade-type spring for each of said sealing elements and wherein. saidsealing elements are in the form of an inverted T with each said spring,bearing against opposite'horizontal arms of one of said elements.

References. Cited. by the Examiner UNITED STATES PATENTS 724,994 4/03Cooley 123 8 827,529 7/06 Hicks 91-105 1 ,350,231 8/20 McFarland 1'23-81,776,452 9/30 Rosenthal'; 103136 2,801,791 8/57 Walter 230 1522,829,603 4/58 Clark 103-136 3 ,070,074 1'2/62 Mallinckrodt 1238 FOREIGNPATENTS 537,506 3/22 France; 21,136,531: 9/62 Germany. 5

15,015 8/26- The Netherlands.

5 8,490 9/ 11' Switzerland.

JOSEPH H. BRANSON, JR.,1 Primary Examiner.

LAURENCE VJEFNER, WILB-UR'J. GOODLIN, Examiners.

1. A ROTARY ENGINE COMPRISING A STATOR HAVING AN INNER WALL WHICHDEFINES A HOLLOW COMPARTMENT, SAID WALL DEFINING IN RADIAL CROSS-SECTIONA PLURALITY OF ANGULARLY ADJOINING CONCAVE RECESSES AND AN INWARDLYPROTRUDING APEX AT EACH POINT OF JUNCTURE BETWEEN TWO ADJOININGRECESSES, A ROTOR MOUNTED WITHIN SAID COMPARTMENT ALONG A LONGITUDINALAXIS WHICH IS PARALLEL TO THE LONGITUDINAL AXIS OF SAID STATOR, SAIDROTOR HAVING A PERIPHERAL SURFACE WHICH DEFINES IN RADIAL CROSS-SECTON APLURALITY OF CONVEX LOBES, EACH LOBE BEING CURVED SUBSTANTIALLY TO THESAME CURVATURE AS EACH OF SAID RECESSES, SAID STATOR COMPRISING ALONGITUDINAL GROOVE AT EACH OF SAID APEXES, A SEALING MEANS IN EACH OFSAID GROOVES, EACH OF SAID SEALING MEANS COM-